Vehicles are typically equipped with a check engine light which notifies the driver that there may be a problem with the operation of the vehicle's engine. Such lights are illuminated when the vehicle's emission sensor determines that the engine may not be running in compliance with predetermined fuel emission standards. However, illumination may occur even when the engine is operating within predetermined emission standards because of a loose fuel cap. Currently, some vehicles are equipped with a sensor to detect the position of the fuel door, and some are equipped with a different sensor to determine if the fuel cap is loose. However, the addition of a second sensor increases vehicle manufacturing costs. Accordingly, it is desirable to have a system and method that can detect the position of a door and warn the driver that the fuel cap may be loose using only one sensor.